From owner-freebsd-questions@freebsd.org Wed Apr 13 23:52:42 2016 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 660F8B0FBCE for ; Wed, 13 Apr 2016 23:52:42 +0000 (UTC) (envelope-from brandon.wandersee@gmail.com) Received: from mail-io0-f169.google.com (mail-io0-f169.google.com [209.85.223.169]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 3DE3C1F9A for ; Wed, 13 Apr 2016 23:52:41 +0000 (UTC) (envelope-from brandon.wandersee@gmail.com) Received: by mail-io0-f169.google.com with SMTP id u185so88034257iod.3 for ; Wed, 13 Apr 2016 16:52:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:references:user-agent:from:to:cc:subject :in-reply-to:date:message-id:mime-version:content-transfer-encoding; bh=pad9GtkRy/gFAMrhGfnDKzhN38clvPnevTsGIVgP6M0=; b=FtXQfCSLk+pBRHAV9tXYUUoDcbHi+FO27dZty9bHuWxcV0MBZGnG68xdLoKpfO9Yya 5EG6UrJxz7vA8VPppvwxd5Ev/MFJNnAXIgU6zhd+mVN2ePyHYEpTM5YBT1p1RdTyTU7B tHRBZIWRgvcBlFPbrtTJvTRakJoJY1Rq5/zL8hsZbvxGz2kygyvFgeRgBMfL2tOA6EZO feS3/d7zIzAhenQfaGdXBf1DM1Noa0j/clqR3tFus/+QWzquFj3THrkm673Y6altJMKN D0M4m0BM4FOpXS+buOMBtiEL4wNfG9F5pf94gSmlR/J/7RSgTj/5Cx0DcQVMBYLy3F1t ZNbg== X-Gm-Message-State: AOPr4FUc5TciI8cFxITjJw43OHEqGZpdAz2FEikd/BL9WUcOuZZNpFccrEUAqEZYf4Zarw== X-Received: by 10.107.8.135 with SMTP id h7mr12228044ioi.85.1460591170158; Wed, 13 Apr 2016 16:46:10 -0700 (PDT) Received: from WorkBox.Home.gmail.com (75-161-218-198.mpls.qwest.net. [75.161.218.198]) by smtp.gmail.com with ESMTPSA id s186sm24723667ios.32.2016.04.13.16.46.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 13 Apr 2016 16:46:09 -0700 (PDT) References: <3qlNxw33PhzRRqR@baobab.bilink.it> <3qlQxr34YhzRRqQ@baobab.bilink.it> User-agent: mu4e 0.9.16; emacs 24.5.1 From: Brandon J. Wandersee To: Luciano Mannucci Cc: freebsd-questions@freebsd.org Subject: Re: ZFS with errors In-reply-to: <3qlQxr34YhzRRqQ@baobab.bilink.it> Date: Wed, 13 Apr 2016 18:46:09 -0500 Message-ID: <86h9f5ax8e.fsf@WorkBox.Home> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 Apr 2016 23:52:42 -0000 Luciano Mannucci writes: > On Wed, 13 Apr 2016 15:56:20 +0200 (CEST) > Trond Endrestøl wrote: > >> There's no redundancy in this pool, making it hard for ZFS to >> automatically repair your files. >> >> Maybe you should destroy your pool and recreate it using a mirrored >> configuration. Maybe, mirror disks 1 & 2, and disks 3 & 4, e.g. > They are of different sizes. I don't know if I can add redundancy > without loosing the bits that exeed the smallest one... > I'm a zfs newbie, just experimenting by now... :) Experimenting is good, but you've sort of dived head-first into the bad practices deep end. A striped ZFS pool consisting of four disks of different sizes is probably *less* reliable (and possibly less performant) than a a single disk formatted with a traditional filesystem. Your data has no redundancy, the pool will only perform as well as the slowest of the four disks, and a problem with any one disk will affect all data. Even a one-disk ZFS stripe with the "copies" property raised is probably better than a large, multi-disk stripe. You can read the original "ZFS Best Practices" guide for some more info.[1] Some of it is either slightly out-of-date, or applies only to Solaris, but most of it is still relevant to FreeBSD today. If you're willing to spend a little money, "FreeBSD Mastery: ZFS" by Michael W. Lucas is pretty good.[2] [1]: http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide [2]: https://www.tiltedwindmillpress.com/?product=fmzfs -- :: Brandon J. Wandersee :: brandon.wandersee@gmail.com :: -------------------------------------------------- :: 'The best design is as little design as possible.' :: --- Dieter Rams ----------------------------------